1. Field of the Invention
The present invention relates to an improvement of a structure of attaching an electric power steering apparatus of a vehicle.
2. Description of Background Art
There is known a conventional structure of attaching an electric power steering apparatus for vehicles where a steering shaft is divided into an upper shaft and a lower shaft, an electrically-operated power steering apparatus is interposed between the upper and lower shafts, and an upper surface of the electrically-operated power steering apparatus is attached to a body frame of the automotive vehicle via a bracket (see Japan Patent No. 2663454
Japan Patent No. 2663454 will be described below.
As shown in FIG. 2 of Japan Patent No. 2663454, an upper portion 7a of a steering shaft 7 is supported by an upper frame pipe 101, and a lower portion 7b of the steering shaft 7 is supported by a lower frame pipe 102. An electrically-operated power steering apparatus 8 is interposed between the upper portion 7a and the lower portion 7b, and the electrically-operated power steering apparatus 8 is attached, with a bolt, to a bracket 9 disposed on the upper frame pipe 101.
The direction in which the bolt is tightened is identical with a direction in which the steering shaft 7 extends.
Although the electrically-operated power steering apparatus 8 is supported by the bracket 9 attached to the upper frame pipe 101, depending on a manufacturing error of the upper frame pipe 101 and the bracket 9, a clearance may be formed between the bracket 9 and an attaching surface of the electrically-operated power steering apparatus 8, or an attaching portion of the bracket 9 may be located below the attaching surface of the electrically-operated power steering apparatus 8, thereby making it difficult to attach the electrically-operated power steering apparatus 8 to the bracket 9. Further, when assisting a steering force, the electrically-operated power steering apparatus 8 receives a rotational force as generated at the steering shaft 7, at the bolt extending perpendicularly to the rotational direction of the steering shaft 7, and thus a shearing force occurs in the bolt. Thus, it is desired to change the direction of tightening of the bolt.